2015 IEEE 15th International Conference on Environment and Electrical Engineering (EEEIC), 2015
ABSTRACT A cathode structure for photon-enhanced thermionic emission was designed for high temper... more ABSTRACT A cathode structure for photon-enhanced thermionic emission was designed for high temperature energy conversion in solar concentrating systems. Surface-hydrogenated diamond is one of the few semiconductors to show negative electron affinity and a work function as low as 1.7 eV if nitrogen-doped, that is connected to a significant thermionic emission at moderate temperatures (up to 800 °C). But diamond is transparent to solar radiation, consequently advanced techniques for preparing an efficient sunlight absorbing diamond are discussed.
Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB), 2008
New solid-state detectors, based on chemical vapour deposited (CVD) polycrystalline diamonds prod... more New solid-state detectors, based on chemical vapour deposited (CVD) polycrystalline diamonds produced by hot-filament (HF) or microwave plasma (MW) assisted deposition methods, were constructed for radiation therapy dosimetry. Properties of diamond crystals, such as high radiation sensitivity, resistance to radiation damage and tissue-equivalence giving a low-energy dependence are very advantageous for clinical dosimetry. Therefore the encapsulation was specially designed for these detectors to have as little influence as possible on the radiation response. The prototypes were irradiated with use of a wide range of photon beam qualities ((60)Co gamma-rays, 6 and 18 MV X-rays). The radiation sensitivity varied considerably between samples deposited with HF (9 nC Gy(-1)mm(-3)) and MW (66 and 144 nC Gy(-1)mm(-3)) methods. For all detectors the leakage current was of the order of 10% of the radiation-induced current (bias voltage 100 V, dose rate 0.3 Gy/min). When irradiated with (60)Co...
ABSTRACT We report the discovery of a nearly-free electronlike resonant state for a β -Si3N4 (000... more ABSTRACT We report the discovery of a nearly-free electronlike resonant state for a β -Si3N4 (0001 )-8 ×8 layer grown on Si(111), as observed by angle-resolved photoemission and scanning tunneling spectroscopy. Comparison with measurements performed on a Si (111 )-7 ×7 surface helped us in the identification of the band. It is found that this parabolic state is degenerate with surface projected bulk bands of the Si(111) substrate.
2015 IEEE 15th International Conference on Environment and Electrical Engineering (EEEIC), 2015
ABSTRACT A cathode structure for photon-enhanced thermionic emission was designed for high temper... more ABSTRACT A cathode structure for photon-enhanced thermionic emission was designed for high temperature energy conversion in solar concentrating systems. Surface-hydrogenated diamond is one of the few semiconductors to show negative electron affinity and a work function as low as 1.7 eV if nitrogen-doped, that is connected to a significant thermionic emission at moderate temperatures (up to 800 °C). But diamond is transparent to solar radiation, consequently advanced techniques for preparing an efficient sunlight absorbing diamond are discussed.
Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB), 2008
New solid-state detectors, based on chemical vapour deposited (CVD) polycrystalline diamonds prod... more New solid-state detectors, based on chemical vapour deposited (CVD) polycrystalline diamonds produced by hot-filament (HF) or microwave plasma (MW) assisted deposition methods, were constructed for radiation therapy dosimetry. Properties of diamond crystals, such as high radiation sensitivity, resistance to radiation damage and tissue-equivalence giving a low-energy dependence are very advantageous for clinical dosimetry. Therefore the encapsulation was specially designed for these detectors to have as little influence as possible on the radiation response. The prototypes were irradiated with use of a wide range of photon beam qualities ((60)Co gamma-rays, 6 and 18 MV X-rays). The radiation sensitivity varied considerably between samples deposited with HF (9 nC Gy(-1)mm(-3)) and MW (66 and 144 nC Gy(-1)mm(-3)) methods. For all detectors the leakage current was of the order of 10% of the radiation-induced current (bias voltage 100 V, dose rate 0.3 Gy/min). When irradiated with (60)Co...
ABSTRACT We report the discovery of a nearly-free electronlike resonant state for a β -Si3N4 (000... more ABSTRACT We report the discovery of a nearly-free electronlike resonant state for a β -Si3N4 (0001 )-8 ×8 layer grown on Si(111), as observed by angle-resolved photoemission and scanning tunneling spectroscopy. Comparison with measurements performed on a Si (111 )-7 ×7 surface helped us in the identification of the band. It is found that this parabolic state is degenerate with surface projected bulk bands of the Si(111) substrate.
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